09-29-2014, 09:15 AM
Make sure and test the clear polyurethane on a piece of scrap, as it might dry slightly with a yellow tint.
Attached is a pic of a foam sign I made this year with several layers of acyclic paint then 3 coats of clear polyurethane. Mine did dry with a yellow/brownish tint, but gives it a weathered feel to the white part. This will not protect the foam like a hard coat, but will give it protection from the rain.
Fellow forum members Duckstruck & Jbaum gave me the same advice about using...